<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Js基础</title>
</head>
<body>
<script type="text/javascript">
	function test1(){
		test2();
	}
	function test2(){
		console.log(arguments.callee.caller);
	}
	test1();
	var a = 'hello word!';
	console.log(a[0]);
</script>
</body>
</html>